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TCP: How to get response from Vb.net server in Android Client?

This is not a possible duplicate. No answer on this site adequately answers or solves my issue.
I am trying to connect to a VB.NET server via TCP socket and get response in Android application. The response is always null as string or -1 as bytes.
I have to connect and get a response for multiple platforms but for the moment I just want to focus on the Android app. Maybe if I figure it out, it will be easier to move forward to other platforms.
I do not have access to edit any code in the VB.NET live server. There system is pretty old and has been only sending responses to other Windows clients up until now.
Here is my Android client. It is inside a background task which is called from the mainActivity. The below command string should return coordinates in the form of a string from the server. Nothing is returned.
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.PrintStream;
import java.io.PrintWriter;
import java.net.Socket;
import java.net.UnknownHostException;
public class Client {
public static void sendMessage() throws IOException, InterruptedException {
Socket socket = null;
String host = "";
int port = ;
PrintStream stream = null;
String command="";
try {
Socket s = new Socket(host,port);
System.out.println("Socket created");
//outgoing stream redirect to socket
OutputStream out = s.getOutputStream();
PrintWriter output = new PrintWriter(out);
output.println(command);
output.flush();
System.out.println("command sent");
BufferedReader input = new BufferedReader(new InputStreamReader(s.getInputStream()));
//read line(s)
System.out.println("Getting response:");
String st = input.readLine();
System.out.println("Response : " + st);
//Close connection
s.close();
}
catch (UnknownHostException e) {
System.out.println("Don't know about host : " + host);
e.printStackTrace();
System.exit(1);
}
catch (IOException e) {
System.out.println("Couldn't get I/O for the connection to : " + host);
e.printStackTrace();
System.exit(1);
}
}
}
A developer also sent me a test client in VB which connects, sends and recieves without problem
Here is a class of a VB:NET Dummy server project the developer has sent me to see how the live server is setup code-wise. I can see it gets the string as unicode but I am not confident in VB to know where my Java code is going wrong.
When I open the project and start the server on localhost I cant connect to it from the java client anyway. Then I have written another client in PHP, same problem, connection established but no response. I downloaded a socket tester software but it also can connect but does not get a response.
Option Explicit On
Imports System
Imports System.Net
Imports System.Net.Sockets
Imports System.Text
Imports Microsoft.VisualBasic
Imports System.Net.Dns
Imports System.Text.UnicodeEncoding
Imports System.Threading
Imports System.Data.SqlClient
Public Enum glenConnectionType
ConstantConnection = 1
ConnectOnDemand = 2
AsyncConnection = 3
End Enum
Public Class clsDynaListner
Public tcpServer As Socket
Public tcpClient As Socket
Public tcpPort As Integer
Public tcpBilnr As Integer ' was shared SHOULD PROB BE INITIALISED TO 0
Public ThreadClient As Thread
Public LastKontakt As Date = Nothing
Public ConActive As Boolean = False
Private tcpClientEndPoint As System.Net.IPEndPoint
Private bCommandLength(15), bReplyLength(15) As Byte
Private iCommandLength, iReplyLength As Integer
Private sReplyLength As String
Private sCommand, sReply As String
Private theCommandBytes() As Byte
Private theReplyBytes() As Byte
Private Const AsyncMaxBytes As Integer = 600000 '1024
Public Shared AsyncData As String = Nothing
Public Sub New(ByVal currentTCPPort As Integer, ByVal theConnectionType As glenConnectionType)
tcpPort = currentTCPPort
tcpClientEndPoint = New System.Net.IPEndPoint(System.Net.IPAddress.Any, tcpPort)
'Select Case theConnectionType
' Case glenConnectionType.ConstantConnection
' ThreadClient = New Threading.Thread(AddressOf ListenForConstantConnection)
' Case glenConnectionType.ConnectOnDemand
ThreadClient = New Threading.Thread(AddressOf ListenForConnectOnDemand)
' Case glenConnectionType.AsyncConnection
'ThreadClient = New Threading.Thread(AddressOf ListenForAsyncConnection)
'End Select
ThreadClient.Start()
End Sub
Private Sub ListenForConnectOnDemand()
While (True)
Try
tcpServer = New Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp)
tcpServer.SendBufferSize = TCP_BUFFER_SIZE
tcpServer.ReceiveBufferSize = TCP_BUFFER_SIZE
tcpServer.Blocking = True
tcpServer.Bind(tcpClientEndPoint)
tcpServer.Listen(0)
tcpClient = tcpServer.Accept
tcpClient.SendBufferSize = TCP_BUFFER_SIZE
tcpClient.ReceiveBufferSize = TCP_BUFFER_SIZE
' Find out how big the command is going to be
tcpClient.Receive(bCommandLength)
iCommandLength = CType(Unicode.GetString(bCommandLength), Integer)
' Bring that command to daddy
Array.Resize(theCommandBytes, iCommandLength + 1)
tcpClient.Receive(theCommandBytes)
sCommand = Unicode.GetString(theCommandBytes)
gInMessage = sCommand
' Get the reply
sReply = "Response:"
gOutMessage = sReply
' Inform the controller of the length of the reply transmission
iReplyLength = (sReply.Length * 2) - 1
sReplyLength = iReplyLength.ToString.PadLeft(8, "0")
bReplyLength = Unicode.GetBytes(sReplyLength)
tcpClient.Send(bReplyLength)
' Send the reply data
Array.Resize(theReplyBytes, iReplyLength + 1)
theReplyBytes = Unicode.GetBytes(sReply)
tcpClient.Send(theReplyBytes)
Array.Clear(theCommandBytes, 0, theCommandBytes.Length)
Array.Clear(theReplyBytes, 0, theReplyBytes.Length)
tcpClient.Close()
tcpServer.Close()
tcpClient = Nothing
tcpServer = Nothing
Catch ex1 As Exception
Try
tcpClient.Close()
tcpServer.Close()
tcpClient = Nothing
tcpServer = Nothing
' ErrMessage = "LisForContr :" & tcpPort.ToString & ex1.Message
Catch
End Try
End Try
End While
End Sub
Protected Overrides Sub Finalize()
Try
tcpServer.Close()
ThreadClient.Abort()
Catch
End Try
MyBase.Finalize()
End Sub
End Class
I have been working with this for a while. The apps I have built are complete for PHP Web App, Android Native, and iPhone Native. The problem is only getting the response from the VB server.
Would like some help to push me in the right direction.
Also I enquired with the developers if the response has a line-break. It does not and it does seem they are willing to mess with the code as it served there purpose for many many years. So I have to find away around that.
If you need me to provide more info just ask.

To send to a VB.NET server from Java you must send the string as unicoded bytes. Send the length at the bytes to expect first and then send the primary data and flush. You have to know exactly what the server is expecting in order to format and encode the data accordingly in preparation to send it.
I was able to successfully fix my issue after debugging VB client and server. This client will process byte arrays, stream advanced sql commands and get the response. The update will be getting xml table data. Anyone who wants to input how to make this client better. You are welcome.
Updated my java client as follows.
/**
* MR-TCP Java & VB.NET DataExchange Client 0.95 - Maze Runner 2015
*/
import java.io.ByteArrayOutputStream;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.net.Socket;
public class Client {
public static String sendCommand(String commandString, Boolean IsID) throws IOException, InterruptedException {
String host;
int port;
String command;
byte[] commandBytes;
String commandLength;
byte[] cmdLengthBytes;
Socket s;
DataOutputStream stream;
String dataString = "";
host = ""; //
port = 0; //
command = commandString;
commandBytes = command.getBytes("UTF-16LE"); // returns byte[18]
if(IsID){
commandLength = "00000021";
cmdLengthBytes = commandLength.getBytes("UTF-16LE");
} else {
String iCommandLength = command; // Get the command length
cmdLengthBytes = iCommandLength.getBytes("UTF-16LE");
int commandNewLength = cmdLengthBytes.length-1;
String newLength = "0000" + String.valueOf(commandNewLength);
cmdLengthBytes = newLength.getBytes("UTF-16LE");
}
try {
s = new Socket(host, port); // Connect to server
//Send the command to the server
stream = new DataOutputStream(s.getOutputStream()); // get ready to send
stream.write(cmdLengthBytes); // tell the server how many bytes to expect
System.out.println("Command length sent");
stream.write(commandBytes); // Send the command to papa...
stream.flush(); // guaranteed sending
System.out.println("Command sent");
//Receive the command from the server.
DataInputStream is = new DataInputStream(s.getInputStream()); // get ready to receive
ByteArrayOutputStream buffer = new ByteArrayOutputStream(); // prepare to get array
int nRead;
byte[] data = new byte[1024];
while ((nRead = is.read(data, 0, data.length)) != -1) { // read the array byte by byte
buffer.write(data, 0, nRead);
}
byte[] dataBytes = buffer.toByteArray(); // get complete array
dataString = buffer.toString("UTF-16LE").substring(8); // get rid of the array length and convert to string
stream.close(); // close the dataStream
s.close(); // close the connection
System.out.println("Disconnected");
} catch (IOException e){
e.printStackTrace();
}
System.out.println("Function Complete");
System.out.println("Server response:" + dataString);
return dataString;
}
}

How to connect a SSL socket through a HTTP proxy?

I'm trying to use Java (Android) to connect to a server with a SSL socket. Please note that this is not HTTP data. This is proprietary protocol with a mix of text and binary data.
I want to relay that SSL connection through a HTTP proxy, but I am facing a lot of problems with that. Right now the scenario that I use and that my browser seems to use with a squid proxy is as follow
[client]->[http connection]->[proxy]->[ssl connection]->[server]
This works for the browser, because after the proxy makes the ssl connection, a TLS negotiation takes place immediately. However my code does not seem to do that.
final TrustManager[] trustManager = new TrustManager[] { new MyX509TrustManager() };
final SSLContext context = SSLContext.getInstance("TLS");
context.init(null, trustManager, null);
SSLSocketFactory factory = context.getSocketFactory();
Socket s = factory.createSocket(new Socket(proxy_ip, 3128), hostName, port, true);
The problem that I have is that createSocket NEVER RETURNS. With a wireshark dump from the proxy machine, I can see that a tcp handshake takes place between the proxy and the server. With dumps from web sessions, I can see that the client usually initiate a SSL handshake at this point, which does not happen in my scenario.
This is not a problem with the trust manager, because the certificate never gets back to me and it is never validated.
EDIT :
After discussion, this is the more complete version of the code I'm trying to run. This version above with the simple (new Socket(...)) as parameter is something I've tried later on.
The original version of the code I'm trying to debug throws
java.net.ConnectException: failed to connect to /192.168.1.100 (port 443): connect failed: ETIMEDOUT (Connection timed out)
The sequence is as follow (a bit simplified again) :
final Socket proxySocket = new Socket();
proxySocket.connect(proxyAddress, 2000); // 2 seconds as the connection timeout for connecting to the proxy server
[Start a thread and write to outputStream=socket.getOutputStream()]
final String proxyRequest = String.format("CONNECT %s:%d HTTP/1.1\r\nProxy-Connection: keep-alive\r\nConnection: keep-alive\r\nHost: %s:%d\r\n\r\n", hostName, port, hostName, port);
outputStream.close(); // Closing or not doesn't change anything
[Stop using that thread and let it exit by reaching the end of its main function]
Then read the response with the following code :
final InputStreamReader isr = new InputStreamReader(proxySocket.getInputStream());
final BufferedReader br = new BufferedReader(isr);
final String statusLine = br.readLine();
boolean proxyConnectSuccess = false;
// readLine consumed the CRLF
final Pattern statusLinePattern = Pattern.compile("^HTTP/\\d+\\.\\d+ (\\d\\d\\d) .*");
final Matcher statusLineMatcher = statusLinePattern.matcher(statusLine);
if (statusLineMatcher.matches())
{
final String statusCode = statusLineMatcher.group(1);
if (null != statusCode && 0 < statusCode.length() && '2' == statusCode.charAt(0))
{
proxyConnectSuccess = true;
}
}
// Consume rest of proxy response
String line;
while ( "".equals((line = br.readLine())) == false )
{
}
I can say that this code works because it works without SSL. The socket created here, proxySocket is the one that is passed to the createSocket function instead of just creating a new one on the fly like in my original example.

java.net.Proxy, or the https.proxyHost/proxyPort properties, only support HTTP proxying via HttpURLConnection, not via a Socket.
To make that work for an SSLSocket of your own, all you need to to is create a plaintext socket, issue an HTTP CONNECT command on it, check the response for 200, and then wrap it in an SSLSocket.
EDIT When sending the CONNECT command, you must not close the socket, of course; and when reading its reply you must not use a BufferedReader, otherwise you will lose data; either read the line by hand or use DataInputStream.readLine(), despite its deprecation. You also need to follow RFC 2616 entirely.

You have to use javax.net lib . you can archive to your target using javax.net.ssl.*.
I think you can get solution using oracle docs. Here is the link for that.
SSLSocketClientWithTunneling

Combine MacDaddy's answer and Viktor Mukhachev's comment, use SSLSocket over a Socket over a Proxy.
Code:
import javax.net.ssl.SSLSocket;
import javax.net.ssl.SSLSocketFactory;
import java.io.IOException;
import java.io.InputStream;
import java.net.InetSocketAddress;
import java.net.Proxy;
import java.net.Socket;
import java.nio.charset.StandardCharsets;
public class SSLThroughProxy {
public static void main(String[] args) throws IOException {
final String REQUEST = "GET / HTTP/1.1\r\n" +
"Host: github.com\r\n" +
"Connection: close\r\n" +
"\r\n";
Proxy proxy = new Proxy(Proxy.Type.HTTP, new InetSocketAddress("your-proxy-host", 8080));
Socket socket = new Socket(proxy);
InetSocketAddress address = new InetSocketAddress("github.com", 443);
socket.connect(address);
SSLSocketFactory sslSocketFactory = (SSLSocketFactory) SSLSocketFactory.getDefault();
SSLSocket sslSocket = (SSLSocket) sslSocketFactory.createSocket(socket, address.getHostName(), address.getPort(), true);
sslSocket.startHandshake();
sslSocket.getOutputStream().write(REQUEST.getBytes());
InputStream inputStream = sslSocket.getInputStream();
byte[] bytes = inputStream.readAllBytes();
System.out.println(new String(bytes, StandardCharsets.UTF_8));
sslSocket.close();
}
}

I don't have time to test/write a targetted solution now, however Upgrading socket to SSLSocket with STARTTLS: recv failed seems to cover the basic problem.
In your case, you need to connect to the proxy, issue a proxy connect, then upgrade the connection - essentially you CONNECT takes the place of the STARTTLS in the referenced question, and the check for " 670 " is not needed.

Basic Java Webserver - Receiving a SocketException: Connection Reset

I've attempted to create a basic HTTP/1.1 compliant web server which supports simple GET requests with persistent connections. I'm getting a SocketException: Connection Reset error occuring at line 61 (if (line==null || line.equals("")). I'm testing it by running it and then directing my chrome browser to localhost portnumber. When I test it with a page with multiple images it seems like only 1 request is being processed before the exception occurs, but I'm not sure what's wrong as this is my first attempt at any kind of socket programming.
Here's my updated Code after removing DataOutputStream:
import java.io.BufferedReader;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.InputStreamReader;
import java.io.ObjectOutputStream;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;
import java.net.URI;
import java.net.URISyntaxException;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.HashMap;
import java.util.StringTokenizer;
public class webserve
{
public static void main(String[] args) throws Exception
{
String rootPath = "~/Documents/MockWebServerDocument/";
int port = 10000;
if(rootPath.startsWith("~" + File.separator))
{
rootPath = System.getProperty("user.home") + rootPath.substring(1);
}
String requestLine="";
StringTokenizer tokens=null;
String line, command;
Date date = new Date();
String connectionStatus="";
//Create new server socket listening on specified port number
ServerSocket serverSocket = new ServerSocket(port);
while(true)
{
//Wait for a client to connect and make a request
Socket connectionSocket = serverSocket.accept();
System.out.println("Socket opened");
//Input stream from client socket
BufferedReader incomingFromClient = new BufferedReader(new InputStreamReader(connectionSocket.getInputStream()));
//PrintWriter to send header to client socket
PrintWriter outgoingHeader = new PrintWriter(connectionSocket.getOutputStream(),true);
//OutputStream to send file data to client socket
ObjectOutputStream outgoingFile = new ObjectOutputStream(connectionSocket.getOutputStream());
//Date format for HTTP Header
SimpleDateFormat HTTPDateFormat = new SimpleDateFormat("EEE MMM d hh:mm:ss zzz yyyy");
//Create a HashMap to store the request header information
HashMap<String,String> requestHeader = new HashMap<String,String>();
while(connectionSocket.isConnected())
{
//requestHeader.clear();
while((line = incomingFromClient.readLine()) != null)
{
if(line.isEmpty())
{
break;
}
//If this is the first line of the request, i.e doesnt contain a colon
if(!(line.contains(":")))
{
requestLine = line;
requestHeader.put("Request", requestLine);
}
else
{
//Otherwise, find the colon in the line and create a key/value pair for the HashMap
int index = line.indexOf(':')+2;
String header = line.substring(0,index-1);
line = line.substring(index).trim();
requestHeader.put(header, line);
System.out.println(header + " " + line);
}
}
connectionStatus = (String)requestHeader.get("Connection:");
requestLine = (String)requestHeader.get("Request");
System.out.println("RequestLine: " + requestLine);
if(!requestLine.equals("")||!(requestLine.equals(null)))
{
tokens = new StringTokenizer(requestLine);
command = tokens.nextToken();
String filename = tokens.nextToken();
filename = cleanUpFilename(filename);
String fullFilepath = rootPath + filename;
System.out.println("Full FilePath: " + fullFilepath);
File file = new File(fullFilepath);
//Get the number of bytes in the file
int numOfBytes=(int)file.length();
//Open a file input stream using the full file pathname
FileInputStream inFile = new FileInputStream(fullFilepath);
//Create byte array to hold file contents
byte[] fileInBytes = new byte[numOfBytes];
inFile.read(fileInBytes,0,numOfBytes);
inFile.close();
//Write the header to the output stream
outgoingHeader.print("HTTP/1.1 200 OK\r\n");
outgoingHeader.print("Date: " + HTTPDateFormat.format(date)+"\r\n");
outgoingHeader.print("Server: BC-Server\r\n");
outgoingHeader.print("Last-Modified: " + HTTPDateFormat.format(file.lastModified())+"\r\n");
outgoingHeader.print("Connection: keep-alive\r\n");
outgoingHeader.print("Content-Length: " + numOfBytes);
outgoingHeader.print("\r\n\r\n");
//When the header has been printed, write the byte array containing the file
//to the output stream
outgoingFile.writeObject(fileInBytes);
if(!(connectionStatus.equals("keep-alive")))
{
System.out.println("Closing: " + connectionStatus);
outgoingHeader.close();
outgoingFile.close();
break;
}
else
continue;
}
}
}
}
public static String cleanUpFilename(String filename)
{
//If there is a "/" at the start of the filename, then remove it
if(filename.charAt(0) == '/')
{
filename = filename.substring(1);
}
//If we are given an absolute URI request, strip all characters
//before the third "/"
if(filename.startsWith("http://"));
{
try
{
URI httpAddress = new URI(filename);
//Get the path from the supplied absolute URI, that is remove
//all character before the third "/"
filename = httpAddress.getPath();
//Again, we may have to trim this modified address if there is an
//extra "/" at the start of the filename
if(filename.charAt(0) == '/')
{
filename = filename.substring(1);
}
}
catch (URISyntaxException e)
{
e.printStackTrace();
}
}
return filename;
}
}
Here's my error trace:
Exception in thread "main" java.net.SocketException: Connection reset
at java.net.SocketInputStream.read(SocketInputStream.java:185)
at sun.nio.cs.StreamDecoder.readBytes(StreamDecoder.java:282)
at sun.nio.cs.StreamDecoder.implRead(StreamDecoder.java:324)
at sun.nio.cs.StreamDecoder.read(StreamDecoder.java:176)
at java.io.InputStreamReader.read(InputStreamReader.java:184)
at java.io.BufferedReader.fill(BufferedReader.java:153)
at java.io.BufferedReader.readLine(BufferedReader.java:316)
at java.io.BufferedReader.readLine(BufferedReader.java:379)
at webserve.main(webserve.java:61)
Any help would be much appreciated, as I'm at a total loss.

Try testing the connection using telnet, wget or curl instead of chrome, because you can then be in control of both sided of the TCP/IP connection.
I think that your web-client is closing the connection from it's side, and you try to read from that socket again (yes, even isConnected() will throw this error when the remote party closed the connection). I am also sorry to say that there is no easy way to combat this other than to catch the exception and handle it gracefully.
This is a problem that often happens with synchronous sockets. Try using java.nio channels and selectors instead.

Using multiple output streams at the same time is highly problematic. In this case you shouldn't create the ObjectOutputStream until you are certain you are going to write an object and you have already written and flushed the headers, because ObjectOutputStream writes a header to the output, which in your present code will appear before any headers, probably causing the client to barf.
In general, SocketException: Connection Reset usually means that you have written to a connection that has already been closed by the peer. As in this case the peer is the client and the client is a Web browser, it can mean anything at all, e.g. the user stopped loading the page, he browsed away, exited the browser, closed the tab. It's not your problem. Just close the socket and forget about it.
For the same reason, your server should also set a reasonable read timeout, like say 10-30 seconds, and bail out if it fires.

The most obvious problem of your server is that it's not multi-threaded. After re-reading your description of the problem, that seems to the be root cause. You need one thread per connection. After serverSocket.accept(), create a new thread to handle the connectionSocket.
while(true)
{
//Wait for a client to connect and make a request
Socket connectionSocket = serverSocket.accept();
new Thread()
{
public void run()
{
//Input stream from client socket
BufferedReader incomingFromClient = ...
etc
}
}.start();

You cannot use DataOutputStream, it's for Java-Java communication. Try Writer for writing headers, and original OutputStream for writing file content.
What's happening is that the browser sees invalid response, and closes the connection. The serve is still writing to the client, which responds RST because the connection is gone.

how to connect to REST web service from Java application

I have to test the EPA's Data Exchange Web Services. Since it is difficult to create 100 accounts, buildings, energy usage distributions, etc. I want to automate the process. I searched for code examples to do a simple GET. The best one I found was at http://pic.dhe.ibm.com/infocenter/tivihelp/v10r1/index.jsp?topic=%2Fcom.ibm.taddm.doc_7.2%2FSDKDevGuide%2Ft_cmdbsdk_restapi_java.html. I modified this for my purposes.
With the certificate, it is throwing an error at that line
Without the certificate (commented out), the connection is timing out and throwing the exception at getResponseCode().
I'm not sure:
What is the correct way of submitting a certificate
If I am sending the credentials correctly
If my code is incomplete, and therefore, the application is unable to get the response code
I should be using Eclipse EE (with Web Tools Platform) and create Project > Web Application, instead of Eclipse Juno (without WTP)
Thank you in advance.
package Package1;
import java.io.*;
import java.util.*;
import java.lang.StringBuffer;
import java.net.*;
import java.net.HttpURLConnection;
import javax.net.ssl.HttpsURLConnection;
public class Class1 {
public static void main (String args[]){
try{
// set this property to the location of the cert file
System.setProperty("javax.net.ssl.trustStore","C:/Documents and Settings/bhattdr/Desktop/-.energystar.gov.der");
String username = "yy777PPP";
String password = "yy777PPP";
String userpass = "";
URL url = new URL("https://portfoliomanager.energystar.gov/wstest/account");
// URLConnection uc = url.openConnection();
HttpsURLConnection uc = (HttpsURLConnection) url.openConnection();
userpass = username + ":" + password;
String basicAuth = "Basic " + javax.xml.bind.DatatypeConverter.printBase64Binary(userpass.getBytes());
System.out.println("sending request...");
uc.setRequestMethod("GET");
uc.setAllowUserInteraction(false);
uc.setDoOutput(true);
uc.setRequestProperty( "Content-type", "text/xml" );
uc.setRequestProperty( "Accept", "text/xml" );
uc.setRequestProperty ("Authorization", basicAuth);
System.out.println(uc.getRequestProperties());
// uc.setRequestProperty( "authorization", "Basic " + encode("administrator:collation"));
// Map headerFields = uc.getHeaderFields();
// System.out.println("header fields are: " + headerFields);
int rspCode = uc.getResponseCode();
if (rspCode == 200) {
InputStream is = uc.getInputStream();
InputStreamReader isr = new InputStreamReader(is);
BufferedReader br = new BufferedReader(isr);
String nextLine = br.readLine();
while (nextLine != null) {
System.out.println(nextLine);
nextLine = br.readLine();
}
}
}
catch(IOException e) {
e.printStackTrace();
}
}
}

You don't need to roll your own.
If you want to write something, you can use Jersey, which has existing classes to act as Rest Clients (Rest clients for Java?)
There are plenty of apps which exercise rest apis which you can use if you don't want to write something. Google turns up plenty (like http://code.google.com/p/rest-client/)

You're using a DER file as your key store which is not supported by Java
Crypto normally. Use the keytool to create a JKS or some other supported keystore and then refer to it.

AMong all the frameworks for REST-Clients... did you try OpenFeign? It's a components from the NetFlix stack. Easy to use and fits into all the other
components of NetFlix.
Give it a try: https://github.com/OpenFeign/feign

HttpsURLConnection and POST

some time ago i wrote this program in python, that logged in a website using https, took some info and logged out.
The program was quite simple:
class Richiesta(object):
def __init__(self,url,data):
self.url = url
self.data = ""
self.content = ""
for k, v in data.iteritems():
self.data += str(k)+"="+str(v)+"&"
if(self.data == ""):
self.req = urllib2.Request(self.url)
else:
self.req = urllib2.Request(self.url,self.data)
self.req.add_header('User-Agent', 'Mozilla/5.0 (Windows NT 5.1; rv:2.0b6) Gecko/20100101 Firefox/4.0b6')
self.req.add_header('Referer', baseurl+'/www/')
self.req.add_header('Cookie', cookie )
def leggi(self):
while(self.content == ""):
try:
r = urllib2.urlopen(self.req)
except urllib2.HTTPError, e:
print("Errore del server, nuovo tentativo tra 15 secondi")
time.sleep(15)
except urllib2.URLError, e:
print("Problema di rete, proverò a riconnettermi tra 20 secondi")
time.sleep(20)
else:
self.content = r.read().decode('utf-8')
def login(username,password):
global cookie
print("Inizio la procedura di login")
url = "https://example.com/auth/Authenticate"
data = {"login":"1","username":username,"password":password}
f = Richiesta(url,data)
f.leggi()
Now, for some reason, I have to translate it in java. Untill now, this is what i've writte:
import java.net.*;
import java.security.Security.*;
import java.io.*;
import javax.net.ssl.*;
public class SafeReq {
String baseurl = "http://www.example.com";
String useragent = "Mozilla/5.0 (Windows NT 5.1; rv:2.0b6) Gecko/20100101 Firefox/4.0b6";
String content = "";
public SafeReq(String s, String sid, String data) throws MalformedURLException {
try{
URL url = new URL(s);
HttpsURLConnection request = ( HttpsURLConnection ) url.openConnection();
request.setUseCaches(false);
request.setDoOutput(true);
request.setDoInput(true);
request.setFollowRedirects(true);
request.setInstanceFollowRedirects(true);
request.setRequestProperty("User-Agent",useragent);
request.setRequestProperty("Referer","http://www.example.com/www/");
request.setRequestProperty("Cookie","sid="+sid);
request.setRequestProperty("Origin","http://www.example.com");
request.setRequestProperty("Content-Type","application/x-www-form-urlencoded");
request.setRequestProperty("Content-length",String.valueOf(data.length()));
request.setRequestMethod("POST");
OutputStreamWriter post = new OutputStreamWriter(request.getOutputStream());
post.write(data);
post.flush();
BufferedReader in = new BufferedReader(new InputStreamReader(request.getInputStream()));
String inputLine;
while ((inputLine = in.readLine()) != null) {
content += inputLine;
}
post.close();
in.close();
} catch (IOException e){
e.printStackTrace();
}
}
public String leggi(){
return content;
}
}
The problem is, the login doesn't work, and when i try to get a page that require me to be logged, i get the "Login Again" message.
The two classes seems quite the same, and i can't understand why i can't make the second one to work ... any idea?

Where do you get your sid from? From the symptoms, I would guess that your session cookie is not passed correctly to the server.
See this question for possible solution: Cookies turned off with Java URLConnection.
In general, I recommend you to use HttpClient for implementing HTTP conversations in Java (anything more complicated than a simple one-time GET or POST). See code examples (I guess "Form based logon" example is appropriate in your case).

Anyone looking for this in the future, take a look at HtmlUnit.
This answer has a nice example.